The invention relates to a metal fixing material bushing.
Metal fixing material bushings are in the state of the art in various designs. By metal fixing material bushings, vacuum-tight sealings of fixing materials are understood, in particular sealings of glasses to metals. The metals act as electric conductors. As representatives, reference is made to U.S. Pat. Nos. 5,345,872 and 3,274,937. Such bushings are common in electronics and in electrical engineering. The glass used for sealing serves as an insulator. Typical metal fixing material bushings are built in such a way, that metallic inner conductors are sealed in a preformed sintered glass part, whereby the sintered glass part or the glass tube in an outer metal part is sealed with the so-called base plate. For example, igniters are preferred applications of such metal fixing material bushings. Said igniters are used among other things for airbags or belt tensioning pulleys in motor vehicles. In this case the metal fixing material bushings are components of an ignition device. In addition to the metal fixing material bushing, the entire ignition device comprises a spark gap, the explosive metal cover, which tightly encapsulates the ignition mechanism. Either one or two or more than two metallic pins can be passed through the bushing. In a preferred implementation with one metallic pin the casing is grounded, in a preferred two-pole embodiment it grounded to one of the pins. The previously described ignition device is used in particular for air bags or belt tensioning pulleys in motor vehicles. Known devices of the named or similar type are described in U.S. Pat. No. 6,274,252, U.S. Pat. No. 5,621,183, DE 29 04 174 A1 or DE 199 27 233 A1, whose disclosure content is fully included in the present application. The previously named ignition units have two metal pins. However, electronic ignition devices are also possible with only a single pin. The ignition devices shown in the state of the art comprise a metal base plate, for example a metal sleeve, which is constructed as a swivel part. The metal base plate exhibits at least one opening through which at least one metal pin is passed. One significant problem of this design consists in the fact that such a design is both material and cost-intensive.
The invention is therefore based on the object of creating a metal fixing material bushing of the initially named type in such a way that it is characterized by a high strength with low material and labor expenses and by a suitability for higher stresses and further that assembly errors, which result from the inaccurate correspondence of the individual elements, are avoided.